planning:non-residential_passive_house_buildings:swimming_pools:energy_efficiency_in_public_indoor_swimming_pools
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planning:non-residential_passive_house_buildings:swimming_pools:energy_efficiency_in_public_indoor_swimming_pools [2014/01/24 09:14] – cweber | planning:non-residential_passive_house_buildings:swimming_pools:energy_efficiency_in_public_indoor_swimming_pools [2014/11/06 17:46] (current) – [See also] cweber | ||
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+ | ====== Energy efficiency in public indoor swimming pools ====== | ||
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+ | ===== Introduction ===== | ||
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+ | Energy consumption in indoor swimming pool buildings is very high on account of high indoor air temperatures, | ||
+ | |||
+ | The potentials for saving energy in swimming pools are not apparent at first, making the optimisation process difficult. On the basis of steady-state calculations (prototype of a multi-zone PHPP calculation), | ||
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+ | An introduction to this topic is provided by a systematic investigation of swimming pool buildings [[http:// | ||
+ | \\ | ||
+ | |||
+ | ===== Basic research based on a demonstration object ===== | ||
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+ | The findings relating to energy flows and different ventilation strategies described in this section are partly based on the results of a dynamic simulation of a simplified Passive House swimming pool building with a pool area of around 900 m² (see Figure 1). The amount of water evaporating during operating times is assumed to be 150 kg/h; outside of operating times this is assumed to be 43 kg/h. This moisture must be removed from the building with as little energy input as possible. As shown in Figure 2, the heating demand of the building is around 900 MWh/a. Assuming that the number of visitors is around 600 per day, and if the quantity of fresh water necessary for a good level of hygiene is taken to be 30 litres per person, almost 530 m³ of fresh water are required for the pool each month. Assuming, in addition, that the water loses evaporative energy, the heating demand of the water for the swimming pool is about 800 MWh each year. \\ | ||
+ | \\ | ||
+ | |{{: | ||
+ | |//**Figure 1: \\ Layout and boundary conditions of the basic swimming pool model**// | ||
+ | \\ | ||
+ | |{{: | ||
+ | |//**Figure 2: \\ Energy balance of the model Passive House swimming pool, \\ assuming dehumidification via ventilation (outdoor air).**// | ||
+ | \\ | ||
+ | |||
+ | ===== Building envelope ===== | ||
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+ | Due to the humid and warm indoor climate, energy flows in swimming pool buildings are different from those in buildings with typical indoor conditions (20-25°C / ~50% RH). While transmission heat losses through the building envelope have the greatest effect on the heating energy balance in the " | ||
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+ | Increasing the indoor air humidity requires that all components of the building envelope are of a high quality in terms of thermal efficiency, because the building component with the lowest surface temperature limits the permissible indoor humidity inside the hall. \\ | ||
+ | \\ | ||
+ | |||
+ | ===== Thermal comfort ===== | ||
+ | |||
+ | Unlike buildings used for residential, | ||
+ | \\ | ||
+ | |{{: | ||
+ | |**//Figure 3: \\ Limit humidity of 14.3 g/kg according to VDI 2089 (German association of engineers) \\ and the limit for a wet person in swimming wear with PMV = 0 or +0.5. \\ \\ In the German building code (EnEV), the maximum humidity is limited by the \\ requirements for structural integrity rather than thermal comfort requirements. \\ For an indoor temperature of 32 °C inside the hall this would equate \\ to a relative humidity of 48 %)//**|\\ | ||
+ | \\ | ||
+ | There are usually different areas with different indoor climate requirements inside a swimming pool building (pool area, changing rooms, entrance hall etc.). If these temperatures differ greatly from each other, thermal decoupling of these different temperature zones by means of insulation of the partition walls and separate ventilation systems is strongly advised, otherwise cross heat flows may lead to undesirable temperatures. This would also increase the transmission and ventilation heat losses significantly. Sufficient planning time should be allowed for the allocation of different zones to different ventilation units, because this creates the fundamental prerequisites for thermal comfort as well as opportunities for saving energy (through regulation of volumetric flows according to demand). When optimising the ventilation units, it is also important to keep in mind the planned setup location inside the building, because the heat recovery efficiency is considerably worsened by long fresh air and exhaust air ducts. Routing and insulation of the supply air ducts must also be taken into account during planning with reference to the surrounding indoor temperatures. \\ | ||
+ | \\ | ||
+ | |||
+ | ===== Energy demand ===== | ||
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+ | There are many aspects of energy efficiency in swimming pool buildings, whereby the space heating demand only forms a part of the total primary energy balance. In addition there is the heating demand of the water and the electricity requirements of the mechanical systems and pool technology. \\ | ||
+ | \\ | ||
+ | |{{: | ||
+ | |//**Figure 4: \\ Example for the final energy demand of a model \\ energy-optimised pool in kWh per treated floor area and year.**// | ||
+ | \\ | ||
+ | Looking at the breakdown of the heating demand into separate areas (Figure 4), it is apparent that the heating demand for the pool water is a determining factor of the model building with the assumed boundary conditions. The largest share of the heat losses from water in the pool is attributable to evaporation enthalpy, even in this optimised case (higher indoor humidity). However, when transferred to the primary energy demand (Figure 5), the ratios change greatly. Although this transfer is based on the project-specific primary energy factors, in most cases it is possible to meet the heating demand with significantly less primary energy expenditure than the electricity demand. Municipalities often own public swimming pools; this opens up possibilities such as the use of combined heat and power plants with waste heat utilisation, | ||
+ | \\ | ||
+ | |||
+ | ==== Air heating demand ==== | ||
+ | |||
+ | Of the different zones of an indoor swimming pool, the hall has the highest heating demand. The highest temperatures (ca. 32°C) are required here and increased air changes are necessary for dehumidification. Particular care must be given to a good quality of the building envelope because the high surface temperatures associated with this permit a relatively high level of humidity inside (up to 64%) without the risk of any structural damage due to condensation. Thus, in comparison with conventionally built indoor swimming pool buildings, the heating demand can be reduced through decreased heat losses from ventilation and transmission, | ||
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+ | As already mentioned, thermal separation of different temperature zones decreases transmission heat losses and, where appropriate, | ||
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+ | Within the framework of the basic research on the implementation of the Passive House concept in public swimming pools [Schulz 2009], the influencing factors which limit the maximum indoor humidity were examined for their applicability in highly insulated buildings on the one hand, and the available savings potentials were studied in the context of ventilation strategies on the other hand. \\ | ||
+ | \\ | ||
+ | |||
+ | ==== Heating demand of the pool ==== | ||
+ | |||
+ | The heating demand of the water in the pool is affected by the surrounding air humidity since higher humidity levels decrease the rate of evaporation, | ||
+ | |||
+ | Through the reduction of waste water e.g. by recovering the filtered water, less fresh (cold) water has to be fed in and heated. This can have a significant effect on the heating demand. Different possibilities are available depending on the filter technique being used. \\ | ||
+ | |||
+ | It is advisable to examine on a project-specific basis whether it is feasible to use other types of waste heat (e.g. that emitted by cooling devices for cold pools) or solar heat for meeting the heating demand of the pool water. \\ | ||
+ | \\ | ||
+ | |||
+ | ==== Heating demand for hot tap water ==== | ||
+ | |||
+ | The heating demand for hot tap water (showers etc.) depends on the distribution and storage losses as well as the amount of hot water required. Water-saving fixtures, controlled operating times for showers, and a good standard of insulation of the pipes form the basis for optimisation. In particular, long circulation lines and circulation periods with a high temperature due to measures for Legionella prevention lead to high losses. \\ | ||
+ | \\ | ||
+ | |||
+ | ==== Auxiliary electricity ==== | ||
+ | |||
+ | Today it should be an unchallenged fact to use frequency converters for pumps. As a rule of thumb, the use of highly efficient technology combined with a well thought-out control strategy should be ensured in order to minimise the demand for auxiliary electricity in all areas of a swimming pool. \\ | ||
+ | |||
+ | === Ventilation === | ||
+ | |||
+ | In the area of ventilation, | ||
+ | |||
+ | In other areas of the building such as showers, changing rooms, lobby and staff rooms, room planning with air transfer zones and demand ventilation control based on moisture and/or CO< | ||
+ | |||
+ | === Swimming pool technology === | ||
+ | |||
+ | The basic principle for saving energy is to use the shortest possible pipe system with low pressure losses. Besides employing highly energy efficient pumps, selecting a good match of pump specifications for the required application also plays a significant role. Pumps for pool water treatment often have two different operating points, for example for water circulation in the pool and for backwashing of the filter. If this results in the pump operating with a lower degree of efficiency most of the time, then it should be checked whether the use of a separate pumps for the different operation modes could lead to energy savings. Sample water extraction and return, linked to the selection of the measuring cell, also offers a potential for saving electricity. When calculating the energy demand, care should be taken that the efficiency of the pump as well as that of the frequency converter and the motor are taken into account. \\ | ||
+ | |||
+ | === Lighting === | ||
+ | |||
+ | The primary and most effective measure for saving energy in relation to lighting is the use of natural light. It should be noted that glazing situated higher up is more effective than glazing at a low level. Windows in the facade are usually inadequate in the case of very deep rooms such as swimming pool halls. Roof lights offer a good opportunity to improve daylight utilisation here. (Domelights of a sufficiently good thermal quality for this purpose are not yet available, unfortunately.). The electricity consumption for artificial lighting should be reduced by means of energy efficient light fixtures, appropriate use of colour, motion sensors, a main switch, and time control etc. \\ | ||
+ | |||
+ | === Other electricity consumptions === | ||
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+ | In order to reduce the electricity consumption of other devices (such as hair dryers, vending machines, elevators, high-pressure cleaners, building management system, CCTV etc.), energy efficient devices should be used and particular attention should be given to control of switch-on times and consumption in standby mode. \\ | ||
+ | \\ | ||
+ | |||
+ | ==== Other areas ==== | ||
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+ | Other leisure activities are often offered in larger swimming pool facilities, resulting in additional energy consumption (e.g. kitchens, saunas, solariums, water attractions such as slides etc.). In the case of water attractions, | ||
+ | \\ | ||
+ | |||
+ | ===== Summary and outlook ===== | ||
+ | |||
+ | The energy consumption in indoor swimming pools is notoriously high, but there is also a huge potential for savings. Initial approaches and interrelationships have been discussed in this article, which are intended to assist designers and architects. These findings are based on calculations and experiences gained from basic research work and the planning process for two pilot projects in Germany (Lippe-Bad in Lünen and Bambados in Bamberg). On the basis of the monitoring carried out for these projects, the Passive House Institute will examine the effectiveness of each of the measures implemented for reducing the energy demand after completion of the pools and will evaluate these. See also the article " | ||
+ | |||
+ | Complex dependencies and interactions between these measures make it very difficult to assess the effectiveness of individual measures and to substantiate these with figures. These measures must be weighed against each other with regard to the savings possible for energy and operation, and a coherent overall concept must be found. The optimum can only be achieved if all specialist planners and contractors involved sit together at one table and if opportunities for active information exchange and discussions are created. This is a fundamental prerequisite which all building owners are expected to meet for a successful project. Investing time to establish a procedure for integrated planning always proves to be worthwhile. \\ | ||
+ | |||
+ | Besides saving energy, the Passive House approach with its highly insulated airtight building envelope provides protection from structural damage - which often occurs in swimming pool buildings - and thus saves costs for maintenance. At this point, it is necessary to draw attention to Energy Performance Contracting for financing - as put into effect in the case of the City of Bremen [Brockmann 2010] for example - particularly for refurbishments of existing indoor swimming pool buildings. \\ | ||
+ | \\ | ||
+ | |||
+ | ===== Literatur ===== | ||
+ | |||
+ | ** [[http:// | ||
+ | |||
+ | **[Brockmann 2010]** Brockmann, | ||
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+ | **[Gagge1986]** Gagge, | ||
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+ | **[VDI 2089]((German association of engineers))** Technische Gebäudeausrüstung von Hallenbädern | ||
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+ | **[ASHRAE2005]** American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE): ASHRAE 2005 Fundamentals. \\ | ||
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+ | **[Heiden/ | ||
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+ | **[[http:// | ||
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+ | **[[http:// | ||
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+ | **[[http:// | ||
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+ | **[[http:// | ||
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+ | \\ | ||
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+ | ====== See also ====== | ||
+ | |||
+ | [[examples: | ||
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+ | [[planning: | ||
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+ | [[planning: | ||
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planning/non-residential_passive_house_buildings/swimming_pools/energy_efficiency_in_public_indoor_swimming_pools.txt · Last modified: 2014/11/06 17:46 by cweber